I don't think a lot of college coaches even try to teach QB's to read defenses anymore. They put a good athlete on the field and then the basic direction is "Check with Us Pre-snap". The coach in the box reads the defense calls down to the field and they signal in the play. In a passing situation there's one "live" receiver and a check down. The QB throws the ball if the receiver is open. If not he looks at the check down if that's covered he either throws it away or tries to make a play with his legs. Kiffin pretty much said that was how he managed Alabama's QB's while he was the OC. That's pretty much how Jones managed Dobbs. That's why so few college QB's arrive in the NFL ready to play. Also the reason WR's don't hustle or run good routes. They're getting the play pre-snap play call too so if their numbers not called many times they're going 1/2 speed. Sure helps an aware safety know where the balls going - to the only guy running all out.
What JG really needs is pocket presence or a real sense of the pressure. Good QB's buy time by simply stepping up or away from the pressure by only taking a step or 2 and keeping their eyes down the field. Too often JG either left the pocket when he still had time, often stepping right into a rusher when the OL had a reasonable block or stood there like a statue and took a lick when a simple stutter step would have avoided the rusher. Part of a QB's job is keeping his OL between himself and a defender. You could put a barrel on the field and Dobbs and Baker Mayfield could keep an OL at bay for 10 seconds just stepping around the barrel. (Hyperbole to make a point) Anyway if JG can stay in the pocket upright long enough to deliver the ball either to the primary receiver, the check down, or by running or throwing the ball away and avoid a negative play he'll have made consequential progress over last year. He needs to do all that in 3 seconds or less.